1. Field of the Invention
The present invention relates to an improved electronic mobile instrument, such as a personal computer, using a detachable battery as a driving source. More particularly, this invention relates to an apparatus and method capable of replacing a drained battery with a spare battery and which does not entail complex switching operations (i.e., turning an electrical switch OFF and ON) and inconvenience of a long waiting time until the electronic mobile instrument restarts its system, as is generally required when an electrical switch is turned OFF and ON.
2. Discussion of the Background
It is well known that a conventional electronic mobile instrument, such as a note book type personal computer (hereinafter referred to as a note book type PC), generally uses a battery as a driving source (electrical power supply) when it is carried outside of an office. The battery is generally detachable to the electronic mobile instrument and capable of being replaced with a spare battery which has been sufficiently charged with electricity, when it has been almost exhausted (i.e., substantially drained). In such a conventional electronic mobile instrument, when the drained battery is replaced with the spare battery, a data generating operation may necessarily be stopped. Therefore data displayed on a display may be removed therefrom and temporarily stored in a memory of the electronic mobile instrument. The electrical switch may then be turned OFF, and the drained battery may be removed from a battery receiving section arranged in the electronic mobile instrument. The spare battery may then be set to the battery receiving section and the electrical switch may be turned ON again so that the electronic mobile instrument can be used again.
However, this operation may force an operator to wait a long time (e.g., a few minutes) until a system of the electronic mobile instrument restarts after the switch is turned ON because a highly developed function of an Operating System (hereinafter referred to as an OS), such as a WINDOWS, is generally installed in the electronic mobile instrument. Accordingly it may take relatively a long time for initializing the system, and an operational efficiency may as a result be greatly lowered. Therefore, a detachable battery is generally strongly expected to last longer.
Further, if a great number of batteries are attached to the electronic mobile instrument, it unavoidably becomes bulky. Further, as described in Laid Open Japanese Patent Applications 6-43974, 4-25914, and 4-195211, it has been proposed to selectively attach a spare battery to the electronic mobile instrument instead of a unit device, such as a floppy disc and a hard disc drives, to make it compact and increase the life of the battery.
However, in such conventional electronic mobile instruments, when the unit device is used in the electronic mobile instrument, and accordingly the spare battery is not attached thereto, the above noted complex battery replacing operation may be required whenever a detachable battery attached thereto as a standard instrument has been substantially drained.